This plaintive ballad was written by Paul Simon so quickly, that he asked himself: "Where did that come from? It doesn't seem like me?" Bridge Over Troubled Water, which topped the American Billboard Hot 100 for a remarkable six weeks, may not have seemed "like me", but the melancholy notes and wondrous lyrics – 'When darkness comes/ And pain is all around/ Like a bridge over troubled water/ I will lay me down' – have come to define Simon and Garfunkel.Rupert Hawksley